Drilling tool



July 25, l95.0 K J. B. RoBERTsoN 2,516,421y

`DRILLING Tool.

Filed Aug. e, 1945 2 sheets-sheet 1 Tu ////%%S *11m '11114 '11.11 '11.14 'Il' A r ,c 3 x* y 36 v Inventor By y M/amy MS July 25, 1950 J. B. ROBERTSON DRILLING TOOL 2 Sheets-Sheet 2 Filed Aug. 6, 1945 I vel/tor 5/9 c( r G L Qemw/zm M/wey el:

Patented July 25, 1950 DRILLING TOOL Jerry B. Robertson, Evansville, Ind.

Application August 6, 1945, Serial No. 609,053

4 Claims.

This invention relates to a drilling tool, and more particularly to the drilling of latcrals extending from the main well hole of an oil or gas well.

The primary object of the invention is to increase the production of an oil or gas well by tapping the surrounding oil or gas bearing sands or rock so as to provide laterals which feed into the main well hole.

Another object of the invention is to drill such laterals from the interior of the well hole Without requiring enlargement thereof.

Among its features my invention embodies a unitary drilling tool which may be lowered into a well casing and below the lower end thereof to a point where the oil or gas bearing deposits may be found, locking the tool in place in the well hole and projecting a drilling head laterally from the casing and into the oil or gas bearing deposits to form a lateral therein through which the fluid may escape into the well hole for subsequent removal.

Other features include means for positively feeding the drill head into the oil or gas bearing deposits, means for driving the drill head, and means for feeding drilling fluid to the drill head during the drilling operation.

Still other features include a prime mover for driving the drill head through the medium of a flexible shaft, means for causing the flexible shaft and drill head to be advanced into the oil or gas bearing deposits, and means for moving the prime mover in unison with the advance of the drill head and flexible shaft as the latter are advanced or retracted.

In the drawings:

Figure 1 is a vertical sectional view through a well hole and casing showing this improved lateral drilling tool in place therein with the drillI head partially advanced into the oil or gas bearing deposits,

Figure 2 is an enlarged fragmentary viewv partly in section of a drill head and the flexible shaft showing the driving connection therebetween,

Figure 3 is a transverse sectional View taken on the line 3--3 of Figure l,

Figure 4 is an enlarged fragmentary sectional view through the lower end of the prime mover showing the connection by which drilling fluid may be introduced into the interior of the flexible shaft,

Figure 5 is a horizontal sectional View taken substantially on the line 5-5 of Figure 1,

' Figure 6 is a fragmentary side view of the exbleshaft and drill head feeding unit,

Figure 7 is a vertical sectional view taken substantially on the line I-l of Figure 5, and

Figure 8 is a perspective view of the flexible shaft and drill head feeding unit.

Referring to the'drawings in detail, a well hole I5 is shown in Figure 1 and the upper portion thereof is lined with the usual casing I 6, while the lower end is uncased so as to permit the fluid to enter the Well hole from the surrounding oil or gas bearing deposits I1. f

In order to improve or increase the production from the well hole I5, I introduce into the .well from the upper open end my drilling tool designated generally I8 which is housed within a tubular housing I9 carrying at its lower end a head or closure having a longitudinal opening 2I formed axially therein. Formed at diametrically opposite points in the cylinder I9 adjacent its L lower end is a pair of vertical slots 22 with which "ses are aligned grooves 23 formed in the upper end of the closure plug 20. Pivotally mounted, as

at 24, in the grooves 23 are diametrically opzposed latch dogs 25 of substantially bel1 crank form, the inner ends of which are fitted into an annular groove 26 formed adjacent the upper end of a plunger rod 21 which is mounted for recip-v rocal motion in the opening 2| yso that when the lower end of the rod 2'I engages the bottom of the well hole I5, the plunger rod will be moved upwardly so as to cause the latch dogs 25 to engage the side walls of the well opening, as illustratedl in Figure 1. In this way, the tubular casing I9` will be locked in the desired position within the well hole.

hereinafter appear.

socket 30 and extending into the tubular casing I9 is a nipple 32 which is provided with an axial opening 33 by means of which communication is established between the interior of the pipe 3| and a flexible hose `34 one end of which is coupled to the nipple 32, as illustrated, while the otherv end leads to a suitable connection by which drilling fluid may be introduced into the interior of, the flexible shaft to be more fully hereinafter described. The cap or plug 29 is provided onl they outside of the coupling 30 with spaced openings, 35 and 36, the purpose of which will more fullyl hereinafter appear.

Formed in the tubular casing I9 in vertically spaced relation to the slots 22 is ani opening 28, the purpose of which will more fully` Mounted for sliding movement in radially spaced channels 31 which are attached to the inner face of the tubular casing I9 is a prime mover 38 which in the present instance takes the form of an electric motor carrying at its upper end a hook 39 to which a suspension cable 40 which leads outwardly through the opening 36 and upwardly through the well hole to the surface of the ground where it may be connected to any suitable suspension device, such'as a windlass (not shown) by means of which the prime mover may be raised or lowered as the operation of the device progresses. the casing of the prime mover 38 is closed by an end member 4I forming a bearing for the axle shaft 42 of the prime mover. A suitable lpacking gland 43 surrounds the shaft 42 adjacent the outer end of the member 4I,'and projecting in axial alignment with the shaft 42 is a tubularA housing 44 which terminates at its lower end in an'internally screw-threaded socket 45 by means of which one end of la flexible shaft assembly 46 iscoupled to the prime mover, it being understood that the inner power shaft assembly of the flexible shaft Y46 is connected -directly to the motor shaft 42. As shown, the diameter of the tubular extension 44 is suflicient to provide a chamber 41 which surrounds the junction of the shaft 42 and assembly 46, and extending laterally from the tubular member 44 is a hollow elbow 48 which terminates in an externally screw-threaded nipple 49 to which the coupling 50 on the end of the hose 34 opposite that which is connected to the nipple 32 is received. It will thus be seen that communication will be established from the interior of the pipe 3| to the chamber 41 and thence to the interior of the flexible shaft assembly 46. Mounted on the end of the flexible shaft assembly v46 is a coupling 5I carrying an antifriction thrust bearing 52 by means of which a rotary rock drilling head designated generally 53 is rotatably supported withv relation to the shaft assembly. This head k53 is provided with a tubular body 54 Vwhich is connected at its inner end to the inner member of the flexible shaft asthe head is rotated by means of the power shaft of the flexible shaft assembly engage the surface to be drilled, as will be readily understood upon reference to Figure l. As shown, the nipple 56 is made hollow so as to establish communication with the `interior of the sleeve 54 whereby the low'of drilling fluid from the interior ofthe flexible shaft assembly 46 through the openings 55, the tubular body 54 and to the cutter`wheel-58 will be established.

In order to feed the cutter 51 laterally through the opening 28 of the casing i9, I employ an arcuate guide and feeding member designated generally '59. This device is best illustrated in Figures to 8, inclusive, and comprises a, prime mover such as an electric motor 6U, to thev drive shaft of which is connected a `suitable speed reduction gearing housed within ahousing 6I which in turn is connected through a worm and wormv wheel 62 and 63, respectively, to -a ,drivevshaft64 The lower or driving end of which is mounted to extend transversely through a guide casing 65. This guide casing 65 is provided with an arcuate channel or passage 66, one end of which opens upwardly in the direction of the prime mover 38, while the opposite end terminates in an enlarged bore 61 which aligns with the opening 28 in the casing I9. Mounted on the shaft B4 and rotatable in a chamber 68 formed in the housing 615 is a roller 69 carrying on its peripheral surface a coating 10 of yielding material which is adapted to engage the casing of the flexible shaft assembly 46, as will be readily seen I upon reference to Figure '7. Mounted on a shaft 1I extending transversely through the guide casing 65 in spaced relation to the shaft 64 is a roller 12 which operates within a chamber 13 and like the roller 69, the roller 'I2 is provided with a yielding coating 'f3 which likewise is adapted to 1 engage the casing of the flexible shaft assembly 46. Carried by the shaft 64 adjacent the end oppositethat to 'which the worm gear 63 is attached is a drive-pinion 14 which operates through a gear train 15 to `drive a gear 16 which is attached to the shaft 1I so that the rollers 69 and 12 Willibe driven in unison. Rotatably mounted in the chamber 11 in the guide member 65 is a cooperating idler roller 18 against which the casing of the flexible shaft assembly 46 runs as it is moved by the yielding surfaces 10 and 13 of the rollers 69 and 12. y

Electrical power is supplied to the motor 6U and to the prime mover 38 by means of the cables 'I9 and 60, respectively, which are joined into a single covering or cable 8| which leads upwardly :through the opening 35 to the surface of the ground and from any suitable source of power. The motor 6I) is preferably of the reversible type so that the flexible shaft assembly 46 and the cutter head 51 may be advanced or retracted at the desire of the user.

In operation, it will be understood that the tool I8 is lowered into the well casing I6 to the desired position in the well hole l5, it being un derstood that the depth to which the device may be lowered is governed by the length of the p1unger21. As soon as the-plunger 21 encounters the bottom of the well hole, the latch dogs 25 will beset so as to lock the device in place and against upward movement. Having thus positioned .the device in the well hole, the motor 38 is set `in operation, thus driving the cutter head 51 through the medium of the drive shaft of thev flexible shaft assembly 46 and upon operating the motor 66 in a direction to advance the cutter head, it will be obvious that a llateral -B2 may be drilled into the oil or' gas bearing deposit l1 to aid in the extraction of the valuable liuids therefrom. Simultaneously with the advance of the cutter 51 drilling Vfluid is admitted to the pipe 3I` and `will ow to the cutter headthrough the flexible hose 34 and the interior of p the flexible shaft assembly 46, thus providing the cutter head with the necessary fluid to wash away the substances which are loosened and thus leave 'a clean lateral through which kthe fluid may be fed to the well hole I5.

.It will thus be Vseen that b y employing this device, the lproduction of a well may be .improved and in some vinstances where the circumstances warrant, a lwell which may have become a dry hole may be restored to production by drilling la-terals into the oil or .gas bearing deposits surrounding ,the well hole.

Whilein the foregoing there has been Ashown and'described the preferred embodiment -of vthis invention, it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to Without departing from the spirit and scope of the invention as claimed.

I claim:

1. A drilling tool for drilling a lateral which communicates with a Well hole comprising a tubular casing adapted to be positioned in a well hole, a slot in said casing, a drill head adapted to be housed Within the tubular casing during its introduction into the Well hole, a flexible shaft in driving connection with said drill head, an arcuate guide Within said casing adjacent said slot through which said flexible shaft extends, drive means movable longitudinally Within said casing above the arcuate guide, said drive means having driving connection with said exible shaft, means carried by said arcuate guide for selectively advancing and retracting the flexible shaft and the drill head With relation to the arcuate guide and the casing, and a cable connected to said drive means and extending through the top of the casing and upwardly through the well to support said drive means Within said casing.

2. A drilling tool adapted to drill a lateral which communicates with a well hole comprising a` tubular casing having a slot therein adapted to be positioned in said well hole, a drill head adapted to be housed Within said tubular casing during its introduction into the well hole, a exible shaft having driving connection with the drill head, an arcuate guide Within the casing adjacent said slot through which said flexible shaft extends, drive means movable longitudinally Within said casing above said arcuate guide, said drive means having driving connection With said flexible shaft, means carried by said arcuate guide for selectively advancing and retracting said flexible shaft and said drill head With relation to said arcuate guide and said casing, and dogs pivoted Within said casingr and operable through said casing to engage opposite sides of the side wall of the well hole to hold the casing in proper position in the well hole.

3. A drilling tool adapted to drill a lateral Which communicates with a well hole comprising a tubular casing havingl a slot therein adapted to be positioned in said Well hole, a drill head adapted to be housed Within said tubular casing during its introduction into the well hole, a flexible shaft having driving connection With the drill head, an arcuate guide Within the casing adjacent said slot through which said ilexible shaft extends, drive means movable longitudinally Within said casing above said arcuate guide, said drive means having driving connection with said exible shaft, a drive roller carried by said arcuate guide for advancing or retracting the flexible shaft and the drill head with relation to the arcuate guide and the casing, and reversible means to drive said drive roller.

4. A drilling tool adapted to drill a lateral which communicates With a Well hole comprising a tubular casing having a slot therein adapted to be positioned in said Well hole, a drill head adapted to be housed Within said tubular casing during its introduction into 'the Well hole, a flexible shaft having driving connection with the drill head, an arcuate guide Within the casing adjacent said slot through which said flexible shaft extends, drive means movable longitudinally within said casing above said arcuate guide, said drive means having driving connection with said exible shaft, means carried by said arcuate guide for selectively advancing and retracting said flexible shaft and said drill head with relation to said arcuate guide and said casing, means pivoted Within said casing and operable therethrough to engage opposite sides of the side Wall of the well hole to hold said casing in proper position in the Well hole, and means to feed drilling iiuid to said drill head supported by said casing.

JERRY B. ROBERTSON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 341,982 Wren May 18, 1886 1,090,919 Kitsee Mar. 24, 1914 1,804,819 Spencer, Jr., et al. May 12, 1931 1,850,403 Lee Mar. 22, 1932 2,181,980 Seale Dec. 5, 1939 2,252,620 DeLong Aug. 12, 1941 2,327,023 Danner Aug. 17, 1943 2,345,816 Hays Apr. 4, 1944 2,372,875 Benke Apr. 3, 1945 

